The invention relates to a method for controlling a power adjustment means of a vehicle engine, in which the vehicle engine is started by the actuation of an ignition starter lock system, the position of an accelerator pedal is converted into an electric signal and the signal proportional to the position of the accelerator pedal is supplied to a control unit which, from the electric signal of the accelerator pedal position and from further measurement signals, generates an output signal for controlling the power adjustment means, and to a device for carrying out the method.
For some time, mechanical systems for power adjustment in vehicles have increasingly been replaced or supplemented by electronic systems. In this case, the transmission of electric signals is substituted for conventional mechanical linkages or Bowden cables. Such an electronic gas system is known, for example, from EP 0,050,707 A1. The power adjustment means of the vehicle engine is designed, there, in the form of a throttle valve, the actuating drive of the throttle valve being controlled by regulating electronics. The regulating electronics receive, as input variables, the electric signal of an accelerator pedal (setpoint generator) for controlling the vehicle speed and further measurement signals which are important for the idling speed. The entire system thus operates by means of purely electric connections between the individual components, with the result that the susceptibility to faults is reduced and restrictions regarding the travel distance between the accelerator pedal, control electronics and power adjustment means are eliminated.
The increasing use of electronic components in motor vehicles has led not only to the replacement of mechanical components, as in the case of the power adjustment means described, but also to the use of entirely new functional devices. The latter include electronics systems for access or driving authorization control, with the aid of which the vehicle is to be prevented from being stolen. WO 92/18732 describes a device which carries out access authorization control. This device contains a first part, which is arranged in the vehicle, and a second part, which is carried by a person. Signal transmission takes place bidirectionally between the two parts. The part to be carried by the person transmits a coded signal which is received and decoded by the part located in the vehicle. When the part located in the vehicle recognizes the signal, a vehicle door is unlocked and the alarm system is cut off, so that it is possible for the vehicle to be used. In these systems, there is the problem that the transmitted signal may be tapped and subsequently misused by unauthorized third parties by means of suitable devices.
Another embodiment of a system for driving authorization control is known from DE 44 34 587 A1. This describes an electronic ignition starter lock system with an electronic ignition starter lock and with an electronic ignition key, the ignition key exchanging coded signals with the ignition lock. Only when the result of the evaluation of the coded signal transmitted is positive will an electromagnetic immobilizer be unlocked and does it become possible for the key to be turned in order to start the vehicle.
This blocking of the key during the transmission and evaluation of the exchanged signals may be irritating to the driver.
The object of the invention is to combine an initially described electronic method for controlling a power adjustment means of a vehicle engine with driving authorization control, specifically in such a way that, on the one hand, a high degree of security is achieved, but, on the other hand, the driver is not irritated by the driving authorization control, and, for the authorized driver, the starting operation takes place virtually unchanged, as compared with vehicles without driving authorization control.
In a method of the introductory-mentioned type for controlling a power adjustment means of a vehicle engine, the object is achieved in that
driving authorization control is started when the ignition starter lock system is actuated,
during the driving authorization control, the output signal from the control unit is formed solely from the further measurement signals, without the signal of the accelerator pedal position being taken into account, and
after the positive conclusion of the driving authorization control, the signal of the accelerator pedal position is taken into account by the control unit in the formation of the output signal, or
after the negative conclusion of the driving authorization control, the starting operation is discontinued by the control unit.
In order to carry out the method according to the invention, a device is provided which contains an accelerator pedal, a converter for converting the accelerator pedal position into an electric signal and a control unit for converting the electric signal of the accelerator pedal position and further measurement signals into an output signal for controlling a power adjustment means of the vehicle engine, there being, furthermore, means for carrying out driving authorization control, which are connected to the control unit in such a way that, during the driving authorization control, the output signal from the control unit is formed solely from the further measurement signals, without the signal of the accelerator pedal position being taken into account.
According to particular embodiments of the device according to the invention, there is provision for the means for driving authorization control to be integrated at least partially into an electronic ignition starter lock system, whilst, particularly in the ignition starter lock system, a wireless exchange of coded data takes place between the ignition lock and an ignition key. There is provision, furthermore, for inductive energy transmission to take place between the ignition lock and the ignition key in order to supply energy to the electronic components integrated in the ignition key.
By means of the specified method and the specified device, driving authorization control systems known per se, which are often also referred to as electronic immobilizers, are combined, according to the invention, with electronic controls, likewise known per se, for power adjustment, so-called xe2x80x9celectronic accelerationxe2x80x9d, in such a way as to achieve both a high degree of security in the driving authorization control and comfortable and reliable starting of the vehicle engine by an authorized driver.